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UNITED STATES DEPARTMENT OF AGRICULTURE
Agricultural Research Administration
Bureau of Agricultural Chemistry and Engineering
U. S. Depa
CHEMICAL CHANGES IN STORED GRAINS
A Selected and Annotated Bibliography
Carol M. Jaeger, Assistant Statistician
Commodity Development Division
Northern Regional Research Laboratory
Peoria , Illinois
The Ever Normal Granary program presupposes the accumulation of larger-
than-normal quantities of grain and its storage for longer-than-usual
periods of time . This program was adopted by the U . S . Department of
Agriculture in 1938, and recently was subscribed to by the three other
major wheat-exporting countries and by Great Britain under the terms of
the World Wheat Agreement of June 27 , 194-2.
The possibility for grain to accumulate under an Ever Normal Granary
program is evidenced by the size of crop carry-overs in the United States
in recent years in comparison with those of former years. In the case
of wheat the July 1 carry-over increased from an average of 238 million
bushels during the 10-year period, 1929-38, to 282 million bushels in
1940, 385 million bushels in 1941, 632 million bushels in 1942, and to
an estimated July 1, 1943 carry-over of 700 million bushels. A similar
tendency is shown for corn. From an average of 212 million bushels for
the 10-year period 1929-38 the October 1 carry-over rose to 583 million
bushels in 1939, 695 million bushels in 1940, 646 million bushels in
1941, and 492 million bushels in 1942.
Evidence that under the Ever Normal Granary program some grain is now
stored longer than one crop season, the former usual limit, may be had
from the Commodity Credit Corporation report of July 1942. This report
shows that the Corporation had in storage approximately 200 million
bushels of 1941 crop wheat and 100 million bushels of 1940 or some
previous crop wheat. Until recently, a similar situation existed with
regard to corn.
Because of the existence of these large accumulations and because of the
war situation necessitating the maintenance of adequate stocks of
grain to meet full domestic, lend-lease, and post-war foreign relief re-
quirements, the possible effect of length of storage on the physical and
chemical properties of grain becomes an important question. A full
knowledge of the character and extent of these changes is necessary for
the proper utilization of such grain.
The Official U. S. Grain Standards have been developed to cover adequate-
ly the changes in the physical aspects of the grain resulting from
storage. But up to the present time not much attention has been given
to chemical changes not reflected in the physical appearance of the
kernels. These chemical changes, however, may be of utmost importance in
the use of the grain both on the farm and in industry. To make available
the sources of information pertaining to this particular aspect of
storage, the following selected and annotated bibliography has been pre-
The sources consulted in preparing this bibliography were limited to
those available at the Northern Regional Research Laboratory.
The literature concerning the effect of storage on the chemical composi-
tion of grain is marked by the dearth of specific results. Up to very
recent years the greatest amount of work seems to have been reported on
the products of grain, principally flour , rather than on the grain it-
On the basis of available information it appears that temperature and
moisture are the fundamental factors concerned with the deterioration
of stored grain and the products therefrom. Type of container or type
of storage, insect infestation, stage of maturity of the grain and its
condition when stored are contributing or secondary factors.
It appears that, in general, wheat with 13 percent or less moisture will
not be damaged by heating in storage, while wheat with more moisture is
likely to be damaged. (See item No. 52). The line between safe and un-
safe storage is not a sharp one and wplll vary with temperature, humidity
of the air, and other factors. In this connection it has been found
that wheat with high moisture content may be stored at 41° F., or lower
temperatures, for many months without suffering damage to its milling
and baking qualities. (See item No. 82). However, under normal tempera-
ture conditions it appears that the baking quality of wheat suffers on
prolonged storage; in some cases showing very marked deterioration.
In the case of all grains or beans it has been found that viability is
maintained for long periods when the commodity is stored with low mois-
ture content at either low or relatively high temperatures.
The available information on the actual chemical changes in stored grain
is not sufficient to support general 'conclusions. Specific experiments
have indicated that the vitamin A content of stored corn decreases by as
much as 50 percent after 3 or 4- years. (See item No. S3). Another
series of experiments showed notable decreases in the percentage of
sugar in stored corn, while for barley and oats small decreases in sugar
content were shown, and for wheat a slight increase was noted. (See
item No. 42) .
Experiments on the chemical changes in stored flour indicate that gluten
quality is affected by the presence of unsaturated fatty acids which
have a tendency to increase when the flour is stored under unfavorable
conditions. (See item Nos. 4, 35, 37, 43, 70, 73). The observed altera-
tions occurring in the proteins from storage of wheat, corn, soybeans and
flour are a decrease in solubility, a partial breakdown of the proteins
as indicated by the amount of nitrogen precipitable by trichloracetic
acid and by an increase in amino nitrogen, and decrease in digestibility.
(See item Nos. 31, 32, 33, 34).
The changes occurring in the carbohydrate and oil constituents as the
result of storage have been discussed only with coincident changes in
CHEMICAL CHANGES IN STORED GRAINS
A Selected and Annotated Bibliography
1. Aamodt, 0. S. , and McCalla, A. G. Quality and keeping properties
of flour from wheat grown on the black and gray soils of Alberta.
Can. Jour. Research. Sec. C. Vol. 13. September 193$.
'Weight per bushel and milling yields of hard red spring wheats
grown on the black soil at Edmonton were the same as for the same
varieties grown on the gray soil at Fallis. Grade, protein content,
and baking quality of Edmonton grown samples were superior. The
flour from most of the Edmonton grown samples retained its quality
for at least two years after milling, but flour from most of the
Fallis grown samples had deteriorated so much during 10 months'
storage that it was unfit for breadmaking. Flour from Reward showed
less deterioration than that from any other standard variety grown
at Fallis. It also had the best original baking quality, and is
the only one of the recommended varieties considered satisfactory
for the gray soil area."
2. Anderson, J. Ansel. Effect of insecticides on wheat quality.
pp. 29-30, Fifteenth Annual Report, Board of Grain Commissioners,
Grain Research Laboratory, Winnipeg, Manitoba. 1942.
"Larvacide, Larvacide mixed with carbon-tetrachloride, Weevil-
cide, Weevil-Insecticide and We s to fume all taint wheat, but the
taints produced do not persist on subsequent aeration. It is be-
lieved that the amount of aeration produced by the normal handling
of fumigated grain will be sufficient to reduce any taint to a
level which is barely perceptible, even if twice the normal dosage
of any of the fumigants is applied. Five times the normal dosage
does not have any apparent injurious effect on either wheat
strength or baking quality."
3. Back, E. A., Cotton, R. T., and Ellington, G. W. Ethylene oxide as
a fumigant for food and other commodities. Jour. Econ. Entomology.
Vol. 23, No. 1, pp. 226-231. February 1930.
"In ethylene oxide, when used as directed, we have a fumigant
which, in addition to possessing freedom from the fire and explo-
sion hazard and extreme toxicity to man, does not appear to leave
in or upon the treated materials obnoxious odors, or residues harm-
ful to man or animals. It is believed that many commodities will
be fumigated more successfully and with less danger when the de-
tails of application, particularly with carbon dioxide, have been
4. Barton-Wright, E. C. Studies on the storage of wheaten flour: III.
Changes in the flora and the fats and the influence of these changes
on gluten character. Cer. Chem. Vol. 15, No. 4, pp. 521-54-1.
"An investigation has been made of the changes that take place
in the bacterial and fungal flora of flour kept under storage condi-
tions. It was found that the bacterial numbers always diminish with
"Deterioration of gluten quality during storage of flour, es-
pecially low-grade flours, was found to depend on the unsaturated
fatty acids present in the oil fraction. In flours with a moisture
content of 16 percent and over, the oil content fell rapidly during
storage and this was found to coincide with increase in fungal
numbers and was not accompanied by deterioration in gluten quality.
"In low-grade flours of normal moisture content (14- to 15 per-
cent) or less with a high oil content it was found that after 6 to
8 weeks' storage the gluten tended to break up on washing, whereas
in the moist samples the gluten improved in quality. This improve-
ment in the quality of the gluten was found to be due to (1) the
removal of fats and fatty acids by fungi and (2) some improving ac-
tion due to the fungi themselves.
"The effect of different saturated and unsaturated fatty acids
on gluten is described and discussed. Saturated acids of high
molecular weight produce only slight shortening effect in gluten.
Unsaturated acids produce serious damage in gluten. This damage is
due to the presence of double bonds in the acid since when these are
removed, e.g., by bromination, the damaging effects are removed.
"Free carboxyl groups are also an essential factor in gluten
damage since this is not caused by esters (e.g. fats themselves) or
by salts of unsaturated fatty acids.
"Gluten damage by unsaturated acids is not due to pH changes as
the effect of, e.g., oleic acid on dough pH is very small (0.1)."
5. Beslcy, H. J., and Baston, G, H. Acidity as a factor in determining
the degree of soundness in corn. U. S. Dcpt. Agr. Bui. No. 102, 1914.
"The degree of acidity of corn should not necessarily be con-
sidered a measure of the percentage of individual kernels that are
visibly damaged. It is the soundness and quality of the corn which
is indicated by the acidity test, and the results of this investiga-
tion suggest the acidity test as a method to be used in determining
accurately the soundness and quality of corn."
A number of tables are presented indicating relationships between
acidity and germination, temperature, destination of corn, etc.
6. Bracken, A. F., and Bailey, C. H. Effect of delayed harvesting
on quality of wheat. Cer. Chen. Vol. 5, No. 2, pp. 128-14-5.
"The baking studies gave proof that wheat which had remained
unharvested in the field for 50 days after ripe, subjected to
alternate wetting and drying, showed no indication of deteriora-
tion as determined by loaf volume and loaf texture.
"Thus it may be stated as a result of these tests that dark
hard wheat of the Turkey Red type does not deteriorate in quality
upon standing uncut in the field when' subjected to alternate
wetting and drying, in spite of the fact that the grains bleach
and lose weight per measured volume."
7. Briggs, Charles H. What do baking tests disclose? Northwestern
Miller. Vol. 6, No. 8, p. 745. August 28, 1929.
"The amount of gluten which the flour contains is often
correlated more nearly with the water absorption than is the mois-
ture content. Again, the water absorption is often inversely
proportional to the amount of soluble carbohydrates (sugars, etc.)
present, which may be taken as a crude measure of the amount of
enzymic action which has taken place, and particularly, though in-
directly, of the proteolytic action that has occurred before the
dough is made and that will occur during fermentation."
8. Cathcart, William H., and Killen, Edward J. Changes in flour on
storage with special reference to the effect of different types of
bags. Cer. Chem. Vol. 16, No. 6, pp. 798-817. 1939.
"Two different samples of chemically bleached and matured
flour were stored separately in four different "types of bags, name-
ly ordinary cotton, paper-lined, jute, and grain. They were stored
under average commercial bake-shop conditions. The samples were
analyzed at regular intervals for moisture, ash, protein, and ab-
sorption, and baking tests were made. The kind of bag had little
effect on the analyses of the baking quality of the flour. In all
cases absorption increased during storage, ash and protein showed
no change, and the baking quality in one sample fell off after the
fourth month and in the other after the sixth month. Deteriora-
tion in the latter case was due to infestation."
9. Coleman, D. A. Unsoundness in wheat. Grain Inspectors' Letter.
June 13, 1931.
"The spoilage of wheat is the direct result of harvesting and
storing of wheat with an excess of moisture. It makes but little
difference whether the wheat is cut and stacked in a wet condition,
or whether the wheat is threshed and stored with excess moisture,
the ultimate results are the same. Stimulated by the high moisture
content in the grain, rapid respiration or fermentation takes place,
heat develops, with the result that the grain spoils, the extent of
the spoilage depending upon hew long the wheat has been exposed to
the fermentation process and how much heat of fermentation has
10. Coleman, D. A., and ^othgeb, B. E. Heat-damaged wheat. U. S. Dept.
Agr. Tech. Bui. No. 6. 1927.
Tables showing the chemical composition of heat-damaged wheat
are given along with data on baking results.
11. Coleman, D. A., Rothgeb, 3. E., and Fellows, H. 0. Respiration of
sorghum grains. U. S. Dcpt. Agr. Tech. Bui. No. 100. 1928.
"Storage tests made under laboratory conditions bear out in a
general way the findings of the respiration studies; namely that if
the temperature is sufficiently high (100° F. or more) sorghum grains
that contain over 14- percent of moisture will go out of condition."
12. Cox, J. Hi The drying for milling purposes of damp and garlicky
wheat. U. S. Dept. Agr. Bui. No. 455. 1916.
"The results of these investigations show practically no bad
effects from the drying of wheat at 140° F. and indicate that this
temperature is probably the most satisfactory for the drying of wheat,
either with or without garlic, for milling purposes."
13. Culbertson, C. C. Debunk fear of old corn. Wallaces' Farmer and
Iowa Homestead. Vol. 67, No. 14, p. 11. July 11, 1942.
C. C. Culbertson, of the Iowa Agricultural Experiment Station,
stated that throughout Iowa during the year there had been cases of
edema etc., apparently caused by feeding vitamin-poor old corn, but
that in most of the edema cases the steers had been getting both old
hay and old corn. If good legume hay is fed along with old com.
there should be no such trouble. In this year's experiment results
showed that there was less difference than was at first indicated in
the feeding of old com compared to new, both with the corn fed
shelled and in combination with alfalfa hay. As a matter of fact, it
was found that some 1937 corn did a little better than the 194-0 corn
because the latter — although three years younger — had dried to a
14. Duvel, J. W. T. The deterioration of corn in storage. U. £. Dept.
Agr. Cir. No. 43. 1909.
15. Fenton, F. C, and Swanson, C. 0. Studies on the qualities of com-
bined wheats as affected by type of bin, moisture and temperature
conditions. Cer. Chem. Vol. 7, pp. 428-448. 1930.
p. 439 - Table shows germination, and composition as affected by
different conditions of storage — (no general conclusions).
16. Fifield, C. C, and Bailey, C. H. The march of acidity in stored
flours. Cer. Chem. Vol. 6, No. 6, pp. 530-40. November 1929.
"It has been generally observed that the acidity of flour
increases progressively with the lapse of time The rate of
change in acidity has appeared to be a function of flour grade,
moisture content, humidity of the atmosphere, temperature, and
possibly other factors."
17. Fisher, E. A., Halton, P., and Carter, R. H. Studies on the
storage of wheaten flour: I. The influence of storage on the
chemical composition and baking quality of flour. Ccr. Chem.
Vol. 14, No." 2, pp. 135-161. March 1937.
"It is well known that wheat flours improve in baking quality
during storage. This improvement continues for some time until
it reaches a maximum, after which progressive deterioration sets
in, the flour becoming eventually unfit for breadmaking. Flours,
even when made from good sound wheat, vary widely in their
response to storage After the first deterioration has pro-
ceeded for some time a second improvement sets in, which in turn
may be followed by a second deterioration. A similar periodicity
occurs in changes observable in many of the chemical properties,
among which may be mentioned hydrogen-ion concentration, buffer
value, total acidity, soluble nitrogen and, above all, in amount
and quality of the washed out gluten. These changes are much more
marked and take place more rapidly the higher the moisture contents
of the flours, and also show very marked differences according to
the nature and grade of the flour Flour which has become use-
less for breadmaking by prolonged storage, or by less prolonged
storage under unsatisf actor;/ conditions, has a marked improving
action when added at the rate of 2 percent to otherwise untreated
flour. The improvements resulting are improved dough body and
stability, improved oven spring, and improved colour, softness and
spring of crumb, and are quite comparable with those brought about
by heat treatment processes, or by the use of over-heat-treated
18. Franke, Erich — head of the production laboratory of the Fleischmann
Yeast Company at Pekin, Illinois. Observations, based on 15 years'
experience in fermentation industries in Czechoslovakia and this
country, on characteristics of stored grains.
Rye and corn begin to show a resistance to malt saccharifica-
tion some 8 or 9 months after harvesting. This resistance remains
essentially the same from then on. Treatment with malt diastase
for a longer time will increase the sac char if ication to the origi-
nal value. Addition of more enzyme will help to a certain extent ,
but will not bring saccharif ication to the original rate. These
observations have been repeated year after year and it is evident
that they are not due to seasonable variations. Experiments have
shown that neither the moisture nor the nitrogen content of the
grains changes. Change in strength of the malt diastase was investi-
gated but showed no difference, indicating the difference to be in
the grain itself.
- It was further noted that during saccharif ication, starch from
fresh grain stained first blue, then violet, then red, and finally
was colorless with iodine, while the old grain went from blue to
colorless without going through the other colors.
In connection with the storage of potatoes for use by dis-
tilleries in the production of alcohol, it was found that the piping
of carbon dioxide from the distillery to the storage bins prolonged
the satisfactory storage period of the potatoes. This obviously
slows down respiration and delays enzymic changes .
19. Geddes, W. F. Discussion before a meeting of the Minneapolis chapter,
Society of Grain Elevator Supt's. - Minneapolis, October 27, 194-2.
Feedstuffs, Vol. 14, No. 45, p. 14. November 7, 1942.
"Regardless of the effects of various mold growths on grain
heating, the grain respiration process is a common cause of damage.
By studies of the carbon dioxide produced, curves have been drawn to
indicate safe moisture limits for various types of grain in storage
when other things are equal. The .'break' in the curve, that is, the
danger point, is reached more rapidly for some grains than others,
the oil content being a major factor in this. Flax, for example, has
the earliest break, rye the latest. Corn curves indicated that at
11 percent moisture virtually no carbon dioxide (cr respiratory heat)
was produced. At 12 percent a small amount is evolved, and at
14 percent a much larger amount was obtained over a given period.
The break occurs there — above 14- percent heating mounts rapidly.
Cereal grains were fairly well grouped, corn being slightly quicker
to heat than others. The tests were conducted at a relatively high
initial temperature . "
Dr. Geddes explained that since oil was not miscible, the mois-
ture content of non-oil portions of grains was higher than would be
indicated by grain weight, thus accounting for the more rapid heat-
ing of grains higher in oil.
ITork on soybeans was begun only last year. Because of its oil
content, its heating curve falls between corn and flaxseed.
20. Grain and Feed Journals. Yi/heat treated with ethylene keeps better.
Grain and Feed Jour., Vol. 88, No. 6, p. 267. March 25, 1942.
"Ein-burning of vfheat having a high moisture content can be re-
tarded by the use of ethylene gas in the storage bins, research
workers of the U. S. Department of Agriculture and the Department of
Milling Industry at Kansas State College have found. The gas, at a
concentration of approximately one part in 10 thousand of air in
the bin was blown into the bin while the damp wheat was being
stored.". . . .
The treatment will reduce the rate of heating and will permit
the farmer or grain handler to store high-moisture wheat for
approximately two weeks, until it can be dried down to a safe mois-
"YVheat that was allowed to mature fully in the field before
harvesting was also included in the ethylene storage research
project. The investigators found that the gas apparently
hastened the ageing process through which wheat must go after
harvesting before it will make flour of satisfactory baking
21. Grain and Feed Journals. Sick wheat. Vol. 89, No. 1, p. 11.
July 8, 1942.
"Sick wheat is but a new name for an old condition result-
ing from storage when damp. Prior to the advent of the combine
when wheat was cut with the binder and stored in barns or stacks
before threshing, sick wheat was usually referred to as mov/-
burned, stack-burned, header damaged. Each condition was usually
accompanied by a musty or sour odor and such wheat was considered
unfit for milling purposes. Briefly stated, the combine plus wet
grain, plus storage,- leads to heating, mustiness and enzymic
action — result sick wheat."
22. Grain & Feed Journals. Watch out for sick wheat. Grain & Feed
Jour. Vol. 89, No. 3, p. 109. August 12, 1942.
"High moisture, and failure to turn wheat sufficiently during
the early weeks of storage are the immediate causes of sick wheat.
0. F. Phillips, Chairman of the Board of Review at Chicago, top
grain supervision office of the U. S. De.pt. Agr. says: 'Sick wheat
is suffocated wheat.. The germ of the wheat berry is a living
organism. It breathes. When suffocated for lack of air, inter-
molecular respiration takes place. This breaks down the starch
cells and the wheat starts to deteriorate. The germ turns color.
It becomes gray, or reddish brown, or black. The bran coat is
soon affected and the berry takes on a dead, lifeless, sometimes
skin burned appearance. If sick wheat is left to natural
processes it becomes heat damaged. Eventually the whole berry
will become black and charred.'"
"Sick wheat is not a new condition that has suddenly dropped
upon us. It is merely another term for an old condition. Other
terms used for the same thing in farm parlance are 'bin-burned' ,
'mow-burned', 'header damaged 1 , and 'stack-burned'. Truth is
that wheat so damaged was left to look after itself when it was
too wet to do so. The result is sick wheat. That was now the
federal department of agriculture officials looked at it back in
1925 when the term 'sick' originated."
23. Grain Inspectors' Letter. Issued from General Field Headquarters,
Grain Division, Bureau of Agricultural Economics. October 1938.
"During harvest- time there was considerable rainfall in a part
of the winter wheat belt. It appears, as a result of this condi-
tion, that quite a volume of wheat with relatively high moisture
content went into farm storage. As a result, there has been more or
less development of storage damage or 'sick wheat', some of which is
now arriving at the various terminal markets . "
24.. Greaves, J. E. Changes in flour during storage. Farm and Home
Science, Vol. 3, No. 2, Utah Agr. Exp. Sta. June 1942.
"In this experiment 13 fifty -pound sacks of flour were
stored for three years."
"The water-soluble phosphorus content of the flour in-
creased and the alcohol soluble phosphorus content decreased as the
flour aged. Therefore, it is evident that during storage there was
a slow breaking down of the complex phosphorus -carrying proteins and
of the fat-carrying phosphorus. Inasmuch as yeast requires large
quantities of phosphorus in its metabolism, it is probable that this
is one of the benefits resulting from the ageing of flour.
"During the early period of storage autolytic changes resulting
in protein cleavage may have been rapid enough to neutralize not
only the acid produced but to have combined with some at first
present. Later protein cleavage may have decreased relative to acid
production with the resulting measurable increase in acidity, or
what is more probable, the acids in the flour were used up in the
normal metabolism of the cell enzymes. This latter supposition im-
plies that the decrease in acidity is owing to the enzymic action
which plays a part in the normal ripening of the wheat. Therefore,
what we have is the normal ripening process, and it does not seem
unreasonable to assume that this enzymic process may occur during the
storage period of flour. Possibly the ripening process is complete
at the point of neutrality and the increase in acidity comes from
decomposition. This may closely correlate with other beneficial
changes occurring in flour, and if sufficiently studied may give an
exact criterion for measuring changes in storages of not only grains
and grain products but also fruits and vegetables.
"In most of the flours the water-soluble carbohydrates increased
owing to storage. Some flours remained unchanged and a few decreased
in water-soluble carbohydrates. Two facts stand out from a study of
the changes in the carbohydrates as the result of storage: (1)
There was a variation in water-soluble reducing sugars occurring in
different flours, and (2) there was a tendency for the water-soluble
carbohydrates to increase during storage, thus indicating a diastatic
action. This increase in soluble sugars results in more available
food for the yeast which breaks the carbohydrates down with the
production of carbon dioxide, so necessary in the leavening of bread.
"Water-soluble basic nitrogen decreased slightly in most flours
as a result of ageing. This may be owing to an actual condensing of
protein resulting in a more elastic gluten."
25. Greaves, J. E., and Hirst, C, T. The influence of storage on the
composition of flour. Utah Agr. Exp. 3ta. Tech. Bui. 19-4, (1925).
C. A. Vol. 20, p. 2031 6 . 1926. *'-
"The H-ion concentration in every flour examined first
decreased and later increased. As deterioration set in there
was increase in the H-ion concentration of the flour. No evi-
dence was obtained by the Sorenson titration method -that protein
cleavage occurs during storage. From 1.39 to 3.52 percent of
the N of these flours occurred as water-soluble basic N. Soluble
carbohydrates increased progressively during the storage period."
26. Greaves, J. E. Changes in stored flour. American Miller, Vol. 54,
p. 376,(1926). C. A. Vol. 20, p. 2031 7 . 1926. *
"At the Utah Experiment Station there were stored thirteen
50-lb. sacks of flour from December 1921 to January 1925
The results indicate that it is only inferior flours which great-
ly increase in acidity during four years' storage. There is a
variation in the water-soluble reducing sugars found in different
flours, and there is a tendency for the water-soluble carbo-
hydrates to increase during storage. The water- absorption power
of these flours increased considerably. Some of the flours yield-
ed a loaf of greater volume after storage, whereas others
registered a shrinkage. The results as a whole point to the con-
clusion that the flours improve in brcadmaking properties on
storage and that this benefit comes from ripening changes brought
about by the action of enzymes on the carbohydrates, fats and
-;:- C. A. abstract checked with bulletin,
27. Gross, Emanuel. Changes in grain seeds during ten years of
storage. Z. Landw. Versuchsw. Vol. 20, p. 4-71 (1917)^
Biedermann's Zentr. Vol. 48, pp. 395-4-00 (1919); C. A. Vol. 14,
p. 2666 7 . 1920.
Wheat, rye, barley, and oats were stored in beakers or in
sacks in an air-dry unheated room Oats and barley increased
in weight while wheat and rye had the same weight per hecto-
liter The water content of barley decreased most, then oats,
rye, and wheat. -Increase in dry weight on storage is explained
by the fact that starch is converted to maltose and dextrin,
which process utilizes water.
28. Hale, W. S., Schwimmer, Sigmund, and Bayfield, E. G. Studies on
treating wheat with ethylene: I. Effect upon high moisture wheat,
Manuscript from Enzyme Research Laboratory. U. S. Dept. of Agr.,
Bur. Agr. Chem. and Eng. 1942.
"As a rule, freshly harvested wheat neither bakes nor germinates
well. A period of storage is necessary to bring either of these
characteristics to the optimum level. Previously reported experi-
ments /Balls and Hale (194-0) 7 have shown that wheat, harvested while
somewhat immature, underwent an almost immediate increase in baking
test and germination capacity when exposed to air containing traces
of ethylene. On the other hand, the flour from immature wheat (be-
fore treatment with ethylene) was not improved by subsequent ex-
posure to the gas, although eventually it improved, like other fresh
flour, on lengthy storage. Thus it seems the effect of ethylene on
the baking test takes place in the whole grain. It is accompanied
by a temporary rise in carbon dioxide output (frequently referred to
as 'respiration'). Furthermore, the effect Is not particularly pro-
nounced on grain already aged in storage."
29. Hoyt, L. F. Further fumigation tests with ethylene dichloride — car-
bon tetrachloride mixture. Ind, and Eng. Chem. Vol. 20, No. 4,
p. 931. September 1928.
"The food products after fumigation show different effects.
Those rich in fat absorbed the fumigant appreciably but on exposure
to the air gradually gave off the fumigant and became edible in 1 to
Results of baking tests on Gold Medal flour showed, "There was
no detectable difference in the odor, texture, or general appearance
of these 'loaves, and although a faint odor of fumigant could be
detected in the flour before use, the fumigant had had no effect on
the quality of the gluten and could not be detected in the finished
Baking tests on whole-grain graham milled from fumigated grain
indicated that "No odor of the fumigant could be detected in the hot
loaf when broken open — the most severe test."
30. Johnson, Arnold H., and Green, Jesse. Wheat and flour studies XVIII.
A study of the nature of the acid responsible for the increase in
acidity which occurs in flours during storage. Cer. Chem. Vol. 3,
pp. 134-H5. 1931.
"It has been known for a long time that flours increase in their
acidity during storage . "
"The H-ion concentration of water extracts of stored flours ex-
tracted with ether were the same as those of the extracts of the
freshly -milled flours.
"The idea is expressed that other-extractable. acids arc alone
responsible for the changes in H-ion concentration or in acidity
(as measured by any method) which occur in flours during storage
under proper conditions.
"The acids removed from flour by extraction with ether must,
on the average, have rather long carbon chains as their coefficient
of distribution between water and ether Was of the order .014 to 1."
31. Jones, D. Broesc, Divine, J. P., and Gersdorff, Chas. E. F. The
effect of storage of corn on the chemical properties of its protein
and on its growth-promoting value. Cer. Chen. Vol. 19, No. 6,
pp. 819-830. November 1942.
"The effects of storage of ground corn and of whole shelled
corn upon the properties of the proteins and upon nutritive
value were determined at various intervals over a storage period
of two years. The results show that three different types of
alterations in the proteins occur: (1) a decrease in the solu-
bility of the proteins, (2) a partial breakdown of the proteins,
indicated by a decrease in true protein content, and (3) a de-
crease in digestibility.
"The extent of the alterations is influenced by temperature,
type of container, duration of storage, and nature of the material
stored. Samples stored at 76° F. were affected more than those
stored at 30° F., and those in bags more than those in sealed
glass jars. Changes in the ground corn were greater than those in
the whole shelled corn. The total nitrogen and free ammonia re-
mained unchanged. The extent of denaturation of the proteins was
measured by determination of solubility in 3 percent NaCl solu-
tion, 70 percent alcohol, and 3 percent sodium salicylate. At
the end of two years' storage in a bag at 76 Q F. the solubility of
the ground-corn protein in NaCl solution and in alcohol was
approximately 60 percent less than that of fresh raaterial. The
true-protein value and digestibility had decreased 32 percent and
29 percent, respectively. Hie rates of the decreases were much
more rapid during the early storage intervals than later.
"Significant decreases in feeding value were also found.
During -a 4-2-day feeding period the average gain in weight of
albino rats fed with ground corn which had been stored for 6
months in jars at 76° F. Tfas 63 g. in comparison with 34 g. for
rats fed with fresh material, and 56 g. for rats fed with
material stored for 12 months. The value remained the same at the
end' of the second year's storage. In every instance less of the
stored material than of the fresh material was consumed by the
same number of rats in the same time. For material stored 6 months,
the gain in weight per gram consumed was the same as for fresh
material. For material stored 12 and 24 months, the gain in weight
per gram consumed was less."
32. Jones, D. Breese, and Gersdorff, Chas. E. F. The effect of storage
on the protein of wheat, white flour, and whole wheat flour. Cer.
Chem. Vol. 18, No. U, pp. 417-434. July 1941.
"The effect of storage- under different conditions upon the pro-
teins of white flour, whole wheat flour, and wheat kernels has been
studied at various intervals over a period of two years. The re-
sults show that three different types of alterations occur; (1) a
decrease in the solubility of the proteins, (2) a partial breakdown
of the proteins indicated by decrease in true protein contunt, by
decrease in the amount of nitrogen precipitablc by trichloracetic
acid, and by increase in amino nitrogen, and (3) decrease in
"The extent of the changes depends on temperature, type of con-
tainers, duration of storage, and the nature of the material stored.
Samples stored at 76° F. were affected more than those stored at
30° F., and those in bags more than those in scaled jars. Changes
in white flour were in general greater than in whole wheat flour.
Significant changes occurred also in the wheat kernels, although not
as great as in the flours. The- total nitrogen and free ammonia re-
mained unchanged. The extent of denaturation of the protuins was
followed by determination of solubility in 3 percent NaCl, 70 percent
alcohol, and 3 percent sodium salicylate. The greatest decrease was
found in solubility of the proteins of white flour in NaCT. When
stored in a bag at 76° F. for two years the percentage decrease
amounted to 61 percent, and 57 percent after similar storage in a
sealed glass jar. The alteration of the proteins is ascribed to the
effect of enzymes and oxidation."
33. Jones , D. Breese, and Gersdorff, Chas. E. F. Changes that occur in
the proteins of soybean meal as a result of storage. Jour. Am. Chem.
Soc. Vol. 60, No. 3, pp. 723-724. 1932.
"Studies have been started to investigate the nature and extent
of changes which occur in the proteins of seeds (both whole and
ground) when stored under different conditions. Results thus far ob-
tained show that marked changes in the chemical properties of the
proteins of ground soybeans occur very soon after grinding. Some of
these changes suggest a decrease in the biological value of the
"By the end of six months the digestibility of the protein
of the low-fat meal stored in bags at 76° had dropped nearly 19 per-
cent below that of the meal when freshly ground. The greatest'
changes occurred at 76° , although at 30° the changes were surprising-
ly high. Greater changes occurred in the meals stored in bags than
in those stored in sealed jars. Of interest is the consistently
greater changes that occurred in the low-fat samples than in the high-
fat samples. The total nitrogen and free ammonium content of all
the samples remained constant throughout the storage periods. The
high-fat samples showed a slight increase in free fatty acids,
particularly in the samples stored at 76° .
"Storage of soybean meal apparently results in partial de-
naturation of the proteins as indicated by their decreased
solubility in salt solution. A proteolysis is also indicated
by the drop in true protein values. The nature of the marked
decrease in digestibility in vitro is being studied."
34. Jones, D. Breese, and Gersdorff, Charles E. F. The effect of
storage on the proteins of seeds and their flours. Soybeans
and wheat. Proc. Am. Soc. Biol. Chemists. Vol. IX, No. 1, p. xlix.
"Marked changes occur in the proteins of seeds on storage or
ageing, the extent varying with the kind of seed and conditions
of storage. Although occurring much more rapidly in flours or
meals, these changes also take place in the unground seeds.
"Defatted soybean meal stored for 1 year in bags at 24.4°
decreased 18 percent in the amount of nitrogen extractable by 10
percent NaCl solution, 21 percent in digestibility, and nearly
12 percent in true protein value. Materially lower percentage
changes occurred at - 1.1°.
"Denaturation of the proteins of wheat and of wheat flours
occurred to a much larger extent and more rapidly than that of
the soybean proteins. After 1 month's storage in sealed jars
at 24.4°, the nitrogen extractable from white flour by 3 percent
NaCl had decreased 43 percent. At the end of 1 year, the per-
centage had dropped to approximately 50 percent. Large decreases
in the amount of nitrogen extrac table with 70 percent alcohol and
Na salicylate also occurred, with similar changes occurring in
whole wheat flour. Indications of extensive proteolysis in the
wheat flours were shown by increased values in amino nitrogen and
decreases in true protein values .and in nitrogen precipitable by
"Changes also occurred in the whole, unground wheat kernels.
After storage in jars at 24-. 4° for 9 months, the percentages of
nitrogen extrac table by NaCl, alcohol, and sodium salicylate had
decreased 26, IS, and 9 percent, respectively. Considerable
proteolysis had also occurred."
35. Kansas Agricultural Experiment Station Tech. Bui. 1. Milling
and baking quality of wheat and flour, pp. 141-142. 1916.
"When wheat undergoes the process of ageing, the gluten
undergoes this desirable transformation. It becomes more elastic
and pliable. The dough from flour made of such wheat is more
easily handled, requires less fermentation and gives a loaf of
larger volume and better texture.
"It seems entirely possible that if wheat is treated with
a certain amount of moisture and then subjected to heat for a short
time this will have the same effect of natural ageing. The amount
of moisture added should have a definite relation to the moisture
content; the higher the moisture content the less the amount of
36. Kelly, C. F., Stahl, B. M., Salmon, S. C, and Black, R. H. "tfheat
storage in experimental farm-type bins. U. S. Dept. Agr. Cir.
No. 637, 245 pp. 1942.
"Various measurements were used to determine the quality of the
wheat during the storage period. The external evidences of wheat
deterioration (such as percent total damage, test weight, odor, etc.)
usually were not apparent until the condition of the grain had been
lowered enough to affect its commercial grade. However, percent
germination and fat acidity of sound wheat were found to be valuable
indices of incipient deterioration that is not apparent from grade
examination, and graphs are presented to show the relation of percent
total damage and percent germination to fat acidity through the
range from 10 to 40 units of fat acidity."
37. Kozmin, Natalie P., Alakrenskaya, Katherin A., and Bondarev, Valerie
D. "Ripening" of wheat flour and its biochemical basis. Muhlenlab.
Vol. 4, pp, 16-32 (1934); C. a. Vol. 28, p. 6207 s . 1934-
"Ripening of the gluten in stored flour causes an increase in
elasticity; gluten of strong flours becomes even more elastic and
short. The effect of storage varies according to the flour type.
The real cause of ripening is the hydrolysis of the fat through the
accumulation of considerable amounts (up to 1 percent) of free un-
saturated acids — oleic, linoleic, linolenic. On removal of these
acids by ether extraction aged flour is 'rejuvenated', i.e. the
original character of the gluten is restored. Conversely the addi-
tion of these acids to fresh flour has a marked ageing effect.
Storage temperature is very important: at 12° -15° the production of
free acids practically ceases ; at 45° the upper limit for the
activity of fat-splitting enzymes is not yet attained. Fat hydroly-
sis occurs independently of the supply of oxygen; in the presence of
oxygen rancidity develops."
38. Kozmin, Natalie P. The ageing of wheat flour and the nature of this
process. Cer. Ch'em. Vol. 12, No. 2, pp. 165-171. March 1935.
"During the storage of flour at a high temperature there could
be observed a strong rise of titratable acidity as well as an in-
crease in the acid number of fat. The content of the free acids in
the fat of this flour amounted to almost 50 percent.
"The removal of fat from the aged flour by ether extraction re-
turned the gluten to its original quality, making it 'young' again."
Conclusions of the experiments are:
"During storage of flour a change in the quality of gluten in
the direction of its strengthening has been observed. The direct
cause of this change is the accumulation of free fatty acids in the
flour, caused by a slow process of fat hydrolysis. The removal of
fatty acids rejuvenates the flour, returning it to its original
"In turn the addition of free unsaturated fatty acids produces
the same effect as natural ageing. Free unsaturated fatty acids
(oleic, linoleic, linolenic, etc.) influence the colloid behavior
of gluten in a specific manner, thickening the gel. Saturated
fatty acids with the same amount of carbon atoms (stearinic,
palmitinic, etc.) show no such effect." (Author probably means
stearic and palmitic acids).
"The process of flour ageing proceeds without participation
of oxygen, as fat hydrolysis does not require the presence of the
same. Oxidation of flour pigments taking place during ageing has
no connection with the change of gluten quality."
"Temperature is the most important factor influencing ageing
of the flour."
39. Kiihl, Hugo, and Kliefoth, D. Storage of wheat flour under different
conditions. Muhlenlab. Vol. 4, pp. 65-70 (1934): 0. A. Vol. 23,
p. 6207 6 . 1934.
"Portions of the same flour, in one case unbleached and un-
treated, and in the other electrically bleached and treated with
KBrt>3, were stored 6 months in tightly packed cloth sacks and in
the form of cylinders compressed at 300 atmospheres. The effect
of admixture of 3 percent wheat germ, both natural and defatted,
on flours thus stored was also determined. The keeping quality
of flour during storage is in every way enhanced by compression
into a solid mass. The keeping quality of flour is influenced
by its fat content, even small admixtures of germ leading to rapid
deterioration. Admixture of defatted germ has little or no effect.
Flour treated with KErO.-a and electrically bleached does not keep so
well as untreated, unbleached flour, and falls off somewhat in
baking quality on storage."
40. Kuhl, Hugo. The effect of long storage on flour. Mehl. u. Brot.
No. 23, pp. 1-5 (1935); Chen. Zentr. Vol. 1, p. 912 (1936);
C. A. Vol. 31, p. 5335-. 1937.
"Storing the flour under a pressure of 300 atmospheres in-
creased its keeping qualities. No moths developed during prolonged
storage and no fungus mold proliferation and no musty odor were evi-
dent. Untreated flour was more stable to storage than that treated
with bromate or electrolytic ally bleached. The fatty acids of the
embryo at first have a favorable, but after a long storage an un-
favorable effect. Wheat embryos freed from their fatty acids by
compression methods decidedly improved the baking qualities of flour
stored for a long period and overcame the undesirable effects of
treatment with bromate and bleaching. Discoloration appearing after
a very long storage is due to the action of the oxidases."
41. Ladd, E. F. Tempering of durum wheat; winter wheat versus spring
wheat. N. Dak. Spec. Bui. Vol. 1, No. 36, pp. 414-415. 1911.
See -reference number 46, this bibliography, for review.
42. Leavitt, ^herman, and Le Clerc, J. A. Change in the composition of
unground cereals during storage. Jour. Ind. and Eng. Chem. Vol. 1,
pp. 299-302. 1909.
The authors found notable decreases in the percentage of sugar
in corn which was stored for 2 years; barley and oats showed small
decreases while wheat and rye changed slightly. Some samples of
wheat showed an actual increase in sugar content. The other con-
stituents changed very little or not at all.
43. Le Clerc, J. A., Wessling, H. h. , Bailey, L. H., and Gordon, W. 0.
Composition and baking value of different particles of flour.
Operative Miller, Vol. 24, pp. 2 57-258. 1919.
"The object of this investigation was to determine the difference,
if any, in the chemical composition and likewise in the baking quali-
ty of the various sized particles of which every flour is com-
posed The following tentative conclusions may be drawn from the
experiments, viz., that in most flours there are three almost dis-
tinct grades t (1) A coarse portion; (2) A very fine portion; (3) A
medium fine portion. It was also found: That less than one-fourth
of the flour belongs to the coarse, one-third to the finest and the
remainder or approximately one-half to the intermediate; that the
quality of the coarse and very fine portions or separates is in-
ferior to that of the intermediate; that the very fine granulate is
by far the poorest part of the flour, both as regards the quantity
and quality of the gluten and as regards the quality of the bread
produced from It; that those portions which remain on the Nos. 18,20
and 21 silks are very similar in gluten content and produce bread of
equally high quality; that in every case the quality of the bread
made from the intermediate granulates is superior to that of the
original flour; that a superior br^ad flour could be made by select-
ing only those granulates which show superior value."
44. McCaig, J. D.^ and McCalla, A. G. Changes in the physical properties
of gluten with ageing of flour. Can. Jour, of Res. Sec. C, Vol. 19,
pp. 163-176. May 1941.
"The pl-rysical properties of gluten, as determined by the hydra-
tion of the gluten between pH 4 and 7, are deleteriously affected by
ageing of flour. Similar effects are obtained by adding linolic acid,
whereas some of the effects of ageing can be removed by extraction of
the flour with ether. The original quality of the gluten is not
restored by such extraction. Gluten from aged deteriorated flour
swells enormously in 0.1N acetic acid; such hydration is not an indi-
cation of good quality but rather of resistance to dispersion. Some
freshly milled flours produce gluten possessing the physical charac-
teristics of gluten from aged deteriorated flour.
"It is concluded that the quality of gluten depends to a
considerable extent on the nature of the absorbed lipoids.
Many of the characteristics of gluten are determined by relative-
ly insoluble (unidentified) lipoid substances, whereas the absence
of such lipoids and the formation of fatty acids during ageing are
deleterious to gluten quality."
45. McCalla, A. G., McCaig, J. D. 3 and Paul, A. D, Effect of various
conditions of storage on baking quality of flour. Can. Jour of
Res. Sec. C, Vol. 17, pp. 452-459. 1939.
- "Flour stored in sealers in a refrigerator at 2° C. did not
change in quality for 22 months after milling. Similar flours
stored in sealers at room temperature deteriorated significantly
within three months, while a third lot stored in snail bags at
room temperature showed first a definite improvement and then
rapid deterioration. At the end of 22 months flours stored in
sacks were much the poorest. Acidity of all flours increased
with storage, but this determination was of little value in es-
timating flour quality."
4-6. Mangels, C. E. Effect of storage on baking quality of common
and durum wheats . Cer. Chem. Vol. 1, No. 4, pp. 169-178.
"A general impression exists that both wheat and flour im-
prove in storage, and this is probably true under certain con-
ditions, A review of the literature indicates that studies on
this point have been rather limited.
"C. E. Saunders (1) V and Shutt (2), of the Ottawa station,
studied the effect of storage on the baking quality of wheat end
flour. Saunders found that both wheat and flour improved in water
absorption and in shape of loaf when stored over long periods.
The author also states 'In regard to loaf volume some irregulari-
ties occurred for which no satisfactory explanation can be
offered at present. '
"Shutt made chemical studies on the wheat and flour samples
used by Saunders and found that total protein and gliadin tend
to increase in storage but the difference is hardly sufficient to
be of significance. No durum wheats were used by Saunders and
Shutt. Saunders in a later report (3) gives the following conclu-
sions: 'The table and outline drawings show clearly that most of
these varieties of wheat are improved very considerably in baking
qualities by long storage, either as wheat or as flour. The highest
1/ Figures in parentheses refer to "bibliography", p. 20
baking strength was attained when the wheat was stored about three
or four years. When the material was stored as flour the changes
were more rapid and the highest baking strength was reached in two
or three years. It appears that by storing the material as flour
a higher bakings trength can be obtained than is possible when the
material is stored as wheat. Ultimately deterioration sets in
rather earlier with the flour than with the wheat, but it is evi-
dent that storage under good conditions is safe for at least ten
years.' The author also states, 'In spite of all the precautions
taken the results show a number of provoking irregularities,' and
these irregularities are ascribed to variation in quality of yeast.
The wheat and flour samples in this case were stored in an unheated
"Snyder (4) stored flour milled from spring and winter wheat in
a dry, we 11- ventilated warehouse, four, eight, and twelve months,
and compared the stored flour with fresh flour milled from similar
wheat. Analyses and baking tests indicated that flour stored under
these conditions shows no deterioration in quality, and a slight im-
provement x;as noted in size and color of loaf.
"Swan's on, Willard, and Fitz (5) stored flour in steam heated
and unheated rooms for comparatively long periods. They find loss
of moisture, but otherwise no significant change in baking quality
"Stockham (6) reports improvement in baking quality of flour
stored in a humid cabinet at 85-95° F. for three "weeks as compared
with original and with flour stored in a dessicator over sulphuric
"Ladd (7) reports results of a storage test with durum patents
and clears. These flours were stored for three months during hot
summer weather (May 17 to August 17, 1911). Six out of seven
samples show a loss in volume, but absorption was higher for all
samples, and color of the clear flours showed marked improvement.
"H. L. White (S) found that flour stored for two years showed
no considerable increase in acidity. The hard "wheat flours main-
tained their baking qualities better than the durum flours, but both
showed decrease in volume ."
Conclusion is that warm storage is more detrimental to flour
quality than cool storage. After 11 months' storage, all lots of
flour showed some deterioration, but the durum flours showed
relatively greater deterioration than the common wheat flours.
"1. (a) Canadian Experimental Farms Report 1907,
(b) Canadian Experimental Farms Report 1909,
(c ) Canadian Experimental Farms Report 1910,
2. Canadian Experimental Farms Report 1911, pp. 163-171.
3. Bulletin 97, pp. 28-38. Department of Agriculture,
Dom. of Can. (1921).
4. Minnesota Agricultural Experiment Station Bulletin 35,
pp. 213-217. (1904).
5. Kansas Agricultural Experiment Station, Bulletin 202,
p. 133. (1915). '
6. North Dakota Special Bulletin. Vol. 2, No. 7,
p. 113. (1912).
7. North Dakota Special Eulletin. Vol. 1, No. 36,
pp. 414-415. (1911).
8. North Dakota Report of Food Coiiimissioner, pp. 140-143-
47. Miege. The maturing of wheat and flour. Compt. rend. acad.
agr. France. Vol, 19, pp. 636-9 (1933); C k. Vol. 27,
p. 4314 3 . 1933.
"The effects of various types of storage on wheat and
flour have been determined. The methods of storage tested have
been: in bags, in bulk, kept covered at a temperature of 21°,
in the air, day and night and in hermetically sealed bottles.
Storage in bulk in the air causes a general improvement of the
quality of the wheat. This is due to a slow oxidation of the
grain reserves which causes a diminution of the carbohydrates
and a modification of the physical properties of the gluten.
Under these conditions there is a lowering of the specific
gravity and an increase in the moisture of the grain. Tenacity
and baking value are greatly improved by storage."
48. National Association of British and Irish Millers Ltd. Corres-
pondence between London representative of U. S. Department of
Agriculture and the Association regarding transactions relating
to "old" wheat. 1931-1932.
In 1931, the fact that United States wheat offered for sale
by the Farm Board was one or two years old was one of the rea-
sons advanced by the National Association of British and Irish
Millers for refusing to accept future deliveries of United States
wheat on a grade basis with grade certificate being prima facie
evidence that delivery was of condition and quality contracted
49. Northwestern Miller. Wheat gets sick. Northwestern Miller.
Vol. 209, No. 2, p. 18a. January 14, 1942.
"In a recent issue of The Piedmont Bulletin, official publica-
tion of the Piedmont Millers Association, some comments on 'sick
wheat' by Charles Molin, supervisor of the Virginia Division of
Markets, are presented."
"Mr. Molin points out that moisture has been an important factor
in the grading of the 194-1 wheat crop in Virginia and expresses the
opinion that some wheat went into storage in mill and farm granaries
with moisture contents higher than normal. The warm weather of the
summer extended well into the fall, and much of the autumn went by
without the occurrence of any considerable cold weather. Such con-
ditions are regarded as furnishing excellent opportunity for the
development of 'sick wheat', and the writer emphasizes the dangers
attending the storage of grain with a moisture content of 14 per-
cent or above.
"Attention is called to the necessity of dissipating the heat
stored in the grain as a result of summer temperatures. It is rec-
ommended that wheat should be cooled to 60° F., or lower, as quickly
as possible, by 'turning' it and passing it over separators, or by
some other means which subjects it to thorough aeration.
"It is pointed out that at temperatures above 60° there is like-
ly to be insect infestation, and that with the rise in temperature
accompanying infestation, the development of sick wheat will progress
"In describing 'sick wheat' , Mr. Molin brought out that 'bin
burnt' indicates a late stage of 'sickness'. It is stated that bin
burnt wheat is unsuitable for milling if the production of good
flour is the objective. Continuing the description, Mr. Molin said,
'The ash and acidity of the flour /from bin burnt wheat / is in-
creased and the quality markedly decreased. However, the good flour-
making properties of wheat have been adversely affected by the
development of sick wheat long before the bin burnt stage is reached.'
"The germ of a healthy kernel is then described as a fatty sub-
stance, the extraction of which from the floury parts of the grain
is dependent upon the flattening of the germ into disc-shaped bodies.
These bodies may be separated from the floury products . ' In sick
wheat', the writer continues, 'the germ tends to pulverize rather
than flatten, and separation is difficult if not impossible. The
germ becomes slightly depressed, and the coating, of a grayish-brown
appearance, rather difficult to detect unless one is on the lookout
with an experienced eye.'
"'If the germ coating is delicately peeled off, the dark-brown
to black powdery appearance of the germ underneath, which has little
resemblance to a healthy germ, may be seen. The general appearance
of such wheat to a casual observer is good, but its milling quali-
ties are disappointing.'"
50. Nature. Storage of National Wheatmeal. Nature, Vol. 149 3 No. 3788.
June 6, 1942.
"A report on the problem of the storage qualities of National
wheatmeal has been published by the Research Association of British
Flour-Millers in Milling of May 23. Storage trials were carried
out over a period of a year and included not only laboratory experi-
ments but also tests under commercial conditions in mills, bakeries
and buffer depots. Moisture content is the most important factor
determining storage life: thus at 14, 14-1/2 and 15-1/2 percent mois-
ture contents, provided the storage conditions are good and a sound
wheat grist is used, the wheatmeals will keep in good condition for
9 months, 4-6 months and 2 months, respectively. Temperature is a
further factor, and whereas at 60° F. a wheatmeal of 15-1/2 percent
moisture remained in good condition for 11 weeks, at 77° F. it kept
only for 3-4 weeks . An additional point of importance revealed by
the experiments is that National wheatmeal is more prone to insect
infestation than white flour."
51. Oklahoma Agricultural and Mechanical College. Agronomists experi-
ment with fumigants for farms. Northwestern Miller. Vol. 211,
No. 8, p. 16. August 19, 1942.
Agronomists from the Oklahoma Agricultural and Mechanical
College have experimented with carbon disulphide as a fumigant.
Because of its extremely high inflammable and explosive proper-
ties it is used for fumigation principally in a mixture with
other fumigants or alone on a farm for treatment of grain in
isolated bins . Workers found that the agent has no significant
effect upon the germination or baking quality of wheat unless
concentrations exceeding four times the recommended rate of approxi-
mately 4 gallons per 1,000 bushels are used. The agronomists state
further that treatments heavy enough to affect germination also
reduced loaf volume and changed the characteristics of the dough.
52.. Parker, John H. wheat quality as affected by farm storage.
Northwestern Miller. Vol. 177, No. 2, p. 118. January 10, 1934.
"Storage damage in wheat is a serious problem at least one
year in five on the average, even in a relatively dry 'wheat grow-
ing area such as central Kansas.
"In general it may be said that wheat with 13 percent or
less moisture will not be damaged by heating in storage, while
that with 14- percent or more moisture is likely to be damaged.
This line is not a sharp one^ and will vary with temperature and
humidity of the air and other factors."
53. Phillips, C. Louise. Heating and spoiling of grain. Part I. Ab-
stracts and references. U. S. Dept. Agr. Bur. Markets and Crop.
Est. Ivlimeo. pp. 1-22. 1921.
54. Phillips, C. Louise. Heating and spoiling of grain. Part II. Ab-
stracts and references. U. S. Dept. Agr. Bur. Markets and Crop Est.
Kimeo. pp. 23-41. 1921.
55. Phillips, C. Louise. Respiration of grain, and its relation to the
heating of grain. Sweat in wheat and flour. Abstracts and
references. U. S. Dept. Agr. Bur. Ag. Econ. Hirneo. 7 pp. 1922.
56. Phillips, 0. F. See reference number 22, this bibliography.
57. Piettre, Maurice. Maturation of grains of wheat.; influence of cer-
tain physicochemical phenomena. Compt. rend. Vol. 198, pp. 608-611.
1934. C. A. Vol. 28, p. 2421 6 . 1934.
The maturation of green wheat grains stored at -5° to -7° is
characterized by a rapid decrease within 4 days, of reducing and
nonreducing sugars, and within 8 days, of globulin and albumin,
coincident with a rapid decrease in water.
58. Rams tad, Paul E and Geddes, W. F. The respiration and storage be-
havior of soybeans. Minn. Agr. Exp. Sta. Tech. Bui. 156. 1942.
"The lowest moisture content at which soybeans were observed to
heat was 15.6 percent. Increases in respiration with time of
storage were marked in soybeans containing over 13 percent moisture
when stored at room temperature; furthermore, the iodine number of
oil from such beans was greatly reduced, although the quantity of oil
did not seem to be diminished. Soybeans remained sound and retained
their viability well at a moisture content of 15.8 percent for a year
and a half when stored at 4° C. On the other hand, when stored at
room temperature, viability 'was seriously diminished even below a
moisture content of 10 percent."
"Rapid loss of viability was caused by conditions which favored
the growth of microorganisms in soybeans. Viability was better re-
tained in beans stored at 15 percent moisture and a temperature of
4° Q. than in beans from the same lot stored at 9 percent moisture
and room temperature. To retain high maximum germination capacity,
soybeans should be stored at a low moisture content (approximately
10 percent) and at as low a temperature as feasible."
59. Robertson, D. W. , Fifield, C. C, and Zeleny, Lawrence. Milling,
baking, and chemical properties of Colorado-grown Marquis and
Kanred wheat stored 9 to 17 years. Jour. Am. Soc. Agron. Vol. 31,
pp. 851-856. 1939.
"Milling and baking tests were made with eight samples of
Marquis wheat and three samples of Kanred wheat stored at Fort
Collins, Colorado, in a dry, unheated room for periods up to
17 years. There was a definite and fairly regular increase in
fat acidity with storage, indicating a certain amount of
progressive deterioration on storage. Satisfactory flour yields
were obtained in all cases and unusual tempering was not re-
quired in any case. All lots made satisfactory bread, there
being no indications of deterioration in baking quality in any
of the samples There was no apparent relation between
deterioration in viability as shown by germination tests and
60. Robertson, D. "17., and Lute, Anna M. Germination of seed of farm
crops in Colorado after storage for various periods of years.
Jour. Am. Soc. Agron. Vol. 29, pp. 822-834. 1937.
"Germination tests were made on the seeds of various farm
crops adapted to Colorado conditions which had been stored in a
dry, unheated room for periods varying from 1 to 15 years.
"The germination percentage of wheat, oats, and barley de-
clined slowly for the first 10-year period with a sharp break
in germination between the 10th and 12th years. The drop in
germination was as great or greater from the tenth to the
fifteenth year as it was from the first to the tenth year."
61. Robertson, D. W. , Lute, A. I.:., and Gardner, Robt. Effect of
relative humidity on viability, moisture content, and respiration
of wheat, oats, and barley seed in storage. Jour. Ag. Res.
Vol. 59, pp. 281-291. 1939.
"The data showing the rates of change of moisture and vi-
ability with humidity offer a means of predicting the maximum
time which would be safe for storage under any given relative-
humidity, assuming temperature conditions comparable to those of
62. Rusca, Ralph A., and Gerdes, Francis L. Effects of artificially
drying seed cotton on certain quality elements of cottonseed in
storage. U. S. Dept. Agr. Cir. No. 651, p. 16. July 1942.
"The conditions under which cottonseed is stored have an im-
portant bearing on the quality of the seed after prolonged periods
of storage. Excessive moisture content and overheating of the
seed not only have an ultimate adverse effect on the quality of oil
extracted from stored seed but they may also influence its germina-
"Results of the 2-year study, in which 23 cottons were used,
have been compiled and analyzed. They indicate that with green,
damp, or wet seed cottons, the process of artificially drying before
ginning did not cause an increase in the rate of deterioration of
the seed in storage; that in fact, it caused retardation of the
formation of free fatty acids. The higher the drying temperature
used, the less was the free fatty acid content of the seed at the end
of the 90-day storage period."
"Germination tests on the undried and dried seed indicate that a
free fa.tty acid content of 2 percent becomes critical as far as
cottonseed germination is concerned."
63. Saunders, C. E. Canadian Experimental Farms Report 1907, pp. 219-223.
See reference number 46, this bibliography, for review.
6/+. Saunders, C. E. Canadian Experimental Farms Report 1909, pp. 204-208.
See reference number 4-6, this bibliography, for review.
65. Saunders, C. E. Canadian Experimental Farms Report 1910, pp. 167-170.
See reference number 46, this bibliography, for review.
66. Saunders, C. E. Dept. of Agr. Dom. of Can. Bui. 97, pp. 23-38. 1921.
See reference number 46, this bibliography, for review.
67. Sayre, J. D. Storage tests with seed corn. Ohio Jour. Sci. Vol. 4-0,
pp. 181-5 (1940); Exp. Sta. Rec. Vol. 85, p. 341. 1941.
"Kernels of Clarage corn, sealed in glass tubes and containing
18 percent moisture, remained viable after 6 years when stored at
temperatures below freezing but died in less than 6 months at room
temperature (about 30° C.) When stored at about 30° C. kernels
stored in oxygen died in 3 years and in nitrogen or carbon dioxide
decreased noticeably in germination, whereas those stored at low-
temperatures in these gases or air gave good germination after 5
68. Sharp, Paul Francis. Wheat and Flour Studies II. Ageing I. The
change in hydrogen-ion concentration of wheat and mill products
with age. Cer. Chem. Vol. 1, No. 3, pp. 117-132. 1924-
"The hydrogen-ion concentration of ground wheat increases more
rapidly than that of unground wheat."
69. Shellenberger, J. A. Variation in the baking quality of wheat during
storage. Cer. Chem. Vol. 16, No. 5, pp. 676-682. September 1939.
"The baking quality of "wheat is improved by storage after harvest ,
but the betterment observed during this investigation was not
particularly impressive. This conclusion is based on the study of
four classes of wheat, obtained from eight states, during the 1938
"The experimental baking test, applied to new "wheat, provides a
reliable indication of the potential baking quality of the crop.
"There appears to be a direct relationship between the viability
of wheat and its baking quality."
70. Shollenberger, J. K., and Marshall, W. K. The effect of storage on
the baking strength of wheat and flour. Unpublished report of mill-
ing investigations. U. 5. Dept. of Agr. Bur. Agr. Econ. 1925.
"The baking results on flours stored in tin cans do not in-
dicate that the length of storage had any appreciable effect upon
the baking strength of the flour. The chemical data on these flour
samples showed a gradual loss in moisture and a tendency to increase
in acidity and water-soluble nitrogen. The proportion of gliadin
to gluten increased while the wet and dry gluten decreased during
the latter part of storage. This decrease in gluten may have been
due to some enzymic action "which decreased its cohesiveness thereby
preventing its full recovery in "washing."
The flours stored in cotton bags shewed marked changes in
baking strength and chemical composition in the latter stages of
The authors state, however, that, "The results of these storage
tests, it is believed, do not point to any very definite conclusions.
In order to obtain more definite conclusions, it would be necessary
to conduct experiments in which the moisture content of the wheat
can be controlled during storage and in a room secure from "weevil
71. Shutt, F. T. Influence of age on wheat and flour. Canadian Ex-
perimental Farms Report 1911, pp. 168-171.
See reference number 4.6, this bibliography, for review.
72. Simpson, D. M. Relation of moisture content and method of storage
to deterioration of stored cottonseed. Jour. Agr. Res. Vol. 50,
pp. 4-4-9-456. 1935.
"Storage experiments with sea-island and upland cottonseed
under the humid conditions prevailing at James Island, South
Carolina, showed that in ordinary storage cottonseed deteriorates
rapidly after two years. A definite relation is indicated between
the moisture condition of the seed during storage and the rapidity
of deterioration. Sea-island seeds, with a moisture content
reduced below 8 percent, when stored in tin containers to prevent
the rapid reabsorption of moisture, retained their germination per-
centage with only slight improvement for 4-1/2 years. Upland cotton-
seed stored under various conditions and containing from 8.7 5 to
13.78 percent moisture deteriorated rapidly when the moisture in the
stored seed remained above 10 percent. Dried seed stored to prevent
reabsorption of moisture showed only slight deterioration after 2-1/2
years. Seeds containing 13.73 percent moisture and stored to prevent
drying were all dead nine months after the beginning of storage."
73. Sinclair, A. T. , and McCalla, A. G. The influence of lipoids on the
quality and keeping properties of flour. Can. Jour. Res. Sec. C,
Vol. 15, pp. 187-203. May 1937.
"The keeping properties of different flours varied considerably.
Ageing was accompanied by increased absorption regardless of whether
the flour deteriorated in baking quality. Increased acidity
developed in all flours, but was not a good measure of deteriora-
tion. Storage in sealed containers favored acidity increases, while
storage in sacks favored deterioration. A decrease in ether extract
accompanied deterioration, while decrease in the less soluble
lipoids appeared to take place in all samples.
"The changes in physical properties of gluten gave the best in-
dication of deterioration. Gluten from deteriorated flour was harsh,
spongy and short, and could not be completely dispersed in sodium
salicylate. Unsaturated fatty acids added to flour had the same-
effects on gluten, but not on baking quality. Ground wheat germ
added to deteriorated flour Improved the gluten and restored its
solubility. The more insoluble germ lipoids were the effective sub-
stances. Alcohol extraction of flour caused deterioration, but
gluten quality was largely restored by addition of germ. All results
indicate the lipoids are absorbed on the protein of the gluten.
"It is concluded that the unique physical properties of gluten
are to a considerable extent dependent on the relatively insoluble
lipoids present. The possibility of gluten denaturation being a
breakdown of the protein-lipoid complex is discussed."
74. Smith , W. D. and others. Artificial drying of rice on the farm.
U. S. Dept. Agr. Cir. No. 292. 1933.
"A drying air temperature of 120° F. can be used without injury
to the rice if the moisture content is reduced only about 2 percent
at each drying operation and the rice is allowed to remain in
storage from 12 to 14 hours between dryings."
75. Snyder, Harry. Yftieat and flour investigations. Minn. Agr. Exp. Sta.
Bui. 85, pp. 213-217. 1904.
■• See reference number 46, this bibliography, for review.
76. Stockham, W. L. Improvement of flour in storage. N. Dak. Spec.
Bui. Vol. 2, No. 7, p. 118. 1912.
See reference number 46, this bibliography, for review.
77. Swans on, A. F. Long time storage of winter wheat. Jour. Am. Soc.
Agron. Vol. 31, No. 10, pp. 896-97. October 1939.
Milling and baking investigations on 11-year old wheat apparent-
ly stored when thoroughly dry and of low moisture content, free
from weevils, and relatively free from cracked grain indicated
that the wheat milled satisfactorily, that it baked a good loaf of
bread, and that the flour gave a dough with a long mixing time and
excellent milling tolerance. The milling and baking results com-
pared favorably with those of the adapted varieties grown in the
same region in 1933.
78. Swanson, C. 0. The milling and baking qualities of a dead wheat.
Northwestern Miller. Vol. I46, p. 154. April 14, 1926.
In referring to wheat which had been stored under favorable
conditions for 25 years, the author states:
"These dead kernels may appear plump and sound, and according
to the milling tests on this dead wheat they may yield a normal
amount of flour. Such dead kernels, however, may increase the per-
cent of ash in the flour and the flour has little value in baking
beyond being a filler."
79. Swanson, C. 0. VJheat and flour quality. Burgess publishing Co.
227 pp. 1938.
"A seed may die and yet the enzyme activity, although reduced,
will persist for a considerable time after the life principle leaves,
like the tools of a mechanic which remain after he is gone. 1'he
diastatic activity of a sample of wheat 42 years old, which had been
dead a long time, since wheat usually dies in less than 10 years,
was found to be 122 milligrams maltose per 10 grams of wheat. Many-
samples of live wheat often give less maltose than this." (p. 83)
"As a rule flour is stored for much shorter period than wheat
and from what is known it is evident that flour does deteriorate
much more rapidly than wheat. It has already been noted that when
the wheat kernel is crushed the enzymes have a greater opportunity
to act on the substrate. The fat in flour is also more exposed to
effects of oxidation. Long storage of flour has shown an increase
in hydrogen-ion concentration. It is generally considered that
flour improves some in baking value after the first few weeks of
storage. Some of these improvements are probably related to the
changes which take place in the lipoids. (p. 126)
80. Swanson, C. 0. Some factors involved in damage to wheat quality.
Cer. Chen. Vol. 11, No. 2, pp. 173-199. March 1934-
"One of the best measures for the extent of damage which has
taken place in wheat Is the determination of the amount of acidity
which has developed in the wheat fat. This is designated as
rancidity. The development of this condition Is, however, related
to the air supply. In the entire exclusion of air this will not
develop. Hence the conditions which favor the development of mold
and rancidity are closely related. However, since damage to quali-
ty also took place in the sealed bottles, absence of high rancidity
is not proof of lack of damage.
"Sugar was not increased until the moisture was above 10 per-
cent. The diastatic activity was not increased by high moisture;
on the contrary, the diastatic activity was greatest in the samples
stored with low moisture. Thus it is not possible to increase
either the sugar content or the diastatic activity by adding water
in amounts which are safe for storage or in .amounts used in temper-
81. Swanson, C. 0. The ever-changing wheat — and the principles of its
handling. Northwestern Miller. Vol. 195, p. 21. September 14, 1938.
""While the exact relationship between loss in viability, u r
germinating power, and quality have not been as extensively demon-
strated as would be desirable, the following statements may be made.
If wheat has a high percent of viability, it has not suffered any
damage due to storage conditions. If the viability is low, it has
suffered some damage, somewhat in proportion to the loss in viability.
If a wheat is dead, the damage may be considerable. The deteriora-
tion in quality, however, does not stop when the 'wheat dies. Hence,
how seriously it is damaged depends on how long it has been dead.
Then it depends on the quality of the wheat at the beginning of
storage . "
82. Swanson, C. 0. The effect of low temperature in preventing damage
to wheat stored with high moisture content. Cer. Chem. Vol. 18,
No. 3, pp. 299-315. May 1941.
"There was no decrease in viability in the samples stored in
the cold (4-1° F.), while all those stored at higher moistures in the
laboratory were dead. Wheat of good viability shows no damage to
its milling and baking qualities Wheat may be stored at 41° F.
at high moisture for many months without suffering any damage to its
milling and baking qualities. When wheat has good viability it
has suffered no damage to the gluten structure even when a slight
odor indicating unsoundness could be detected."
83. Swans on, C. 0. Effects of moisture on the physical and other
properties of wheat. Cer. Chem. Vol. 18, No. 6, pp. 705-729.
Results from exposing wheat before threshing to various
amounts of moisture and also from wetting threshed wheat grain
to various moisture percentages from one to six times show that
the greatest apparent effects were a lowering of test weight and
a decrease in vitreous condition. The hardness as determined by
the barley pearler was also decreased. Since these properties
are important grain grading factors, wetting wheat either arti-
ficially or by exposure to rain or by adding water to the grain
and then drying did seriously affect the grading values of the
"The decreases in test weight were not reflected in corres-
pondingly lower flour yields in the samples wetted after threshing.
The samples wetted as grain, the test weights of which had been
reduced as much as 6 pounds, gave essentially as high flour yields
as the samples not wetted or those wetted comparatively little.
This was not due to closer milling, since the ash figures varied
only within the experimental limits Because there was no loss
of material, there should have been no decrease in flour yield
simply because the space occupied by the kernels in the test
kettle had been increased.
"The baking values obtained on representative samples did not
correlate with the commercial grade of the grain nor with the
severity of the treatment The curves made on the recording
dough mixer showed a longer time of development and a decrease in
height as a result of the more severe treatments."
84. Swans on, C. 0., and Fenton, F. C. The quality of wheat as affect-
ed by farm storage. Kansas Agr. Exp. Sta. Tech. Bui. 33. 1932.
Tables are given showing the effect of damage resulting from
storage on the chemical composition of wheat.
85. Swanson, C. 0., Willard, J. T. , and Fitz, L. A. Kansas flours;
Chemical, baking, and storage tests. Kansas Agr. Exp. Sta. Bui.
No. 202, p. 133. 1915.
See reference number 46, of this bibliography, for review.
86. Thomas, R. C. The role of certain fungi in the "sick wheat" problem.
Ohio Bimonthly Bui. Vol. 22, No, 185, pp. 43-45. 1937.
"It is evident from this study that there is a great difference
in the toxic effect of the byproducts of growth of various fungi,
including molds, upon the viability of wheat. All of the organisms
used have been found to be commonly associated with grains both in
the field and in storage. This association becomes significant only
when the moisture content of the grain is high and the temperature
favorable for mold growth. Two strains of ;i.spergilli have been
found to elaborate toxic products when grown upon bran. The toxicity
of these products was demonstrated by the reduction of viability of
normal wheat. What further changes these molds may cause in bring-
ing about the condition known as 'sick wheat', rendering the grain
inferior and milled products below standard, remain to be seen."
87. U. S. Dept. Agr. Clip Sheet No. 1253. Store soybeans dry. Release
July 5, 1942.
"Soybean seed stored in bulk sometimes loses viability — the
ability to sprout — to a serious extent. Tests by the U. S. D. A. in
different regions indicate that this is mainly a matter of controll-
ing the storage temperature and seed moisture. One lot of soybean
seeds with 8 or 9 percent moisture, held at 35° F. for 8 years
suffered no loss in viability, whereas another batch, with 13 or 14
percent moisture, held at 70° P., showed no germination after 20
months . "
88. Wallaces' Farmer and Iowa Homestead. Don't give steers old feed,
p. 3. April 13, 1942.
"Feeding beef steers exclusively on hay and corn that are
several years old is now regarded as an unwise practice. Such feeds
may have depreciated so much in vitamin content that the animals will
develop edema, or swelling of the legs and quarters. Such affected
animals may be condemned when shipped to market, and often sone will
die in the feed-lot."
The Illinois Experiment Station also reports that beef cattle
fed on three and four-year-old corn thrive well for some time, until
their front legs begin to swell. Lameness, loss of appetite and
rapid loss of flesh are other symptoms.
Chemical analysis of old yellow corn by Illinois Experiment
Station workers has shown Vitamin A content only half as great as in
89. White, H. L. N. Dak. Report of Food Commissioner , pp. 140-14-3. 1911.
See reference number 4-6, this bibliography, for review.
90. Zeleny, Lawrence, and Coleman, D. A. Acidity in cereals and cereal
products, its determination and significance. Cer. Chem. Vol. 15,
pp. 580-595. 1938.
"The Bureau of Agricultural Economics, in an effort to improve
existing methods for evaluating quality of the cereal grains, has
been making a study of acidity as a possible practical indication of
deteriorative changes occurring in the grain."
"The acidic substances present in cereals and cereal products
may be divided into three principal classes: (1) free fatty acids
(2) acid phosphates and (3) amino acids. These acids are present in
small quantities in all normal grain and under certain conditions
increase in amount chiefly by virtue of the enzymatic hydrolysis of
fats, phytin, and proteins, respectively."
"A study of the individual acidity fractions in 24-6 samples of
corn and of the same fractions in wheat undergoing deterioration in
storage reveals the fact that only the fat acidity increases
significantly during the early stages of spoilage."
"Fat acidity alone appears to be a more reliable index of sound-
ness in grain than either of the 'other types of acid present, or than
any combination of these acid fractions as determined by any of the
commonly used methods."
91. Zeleny, Lawrence. Fat acidity in relation to heating of corn in
storage. Cer. Chem. Vol. 17, pp. 29-37. 194-0. C. A. Vol. 34 ,
p. 2090. 194-0. -::-
"The rate at which heat is developed depends upon the moisture
content of the grain, the temperature, the available 02 supply, and
upon certain characteristics of the grain itself, which are not
completely understood. The acidity of grain, particularly of corn,
is a more reliable measure of its degree of soundness than other
available chemical or physical tests. Fat acidity is expressed in
terms of mg. of KOH required to neutralize the free fatty acids
extracted from 100 g. of corn calculated to a dry matter basis.
The rate of spontaneous heating of grain can be predicted much more
C. A. abstract checked with Cer. Chem. publication.
accurately when moisture and fat acidity are considered together than
with moisture alone. It was shown that corn with a moisture content
of 17 percent and a fat acidity of 100 can be expected to heat in
storage as rapidly as corn with a moisture content of 21 percent and
a fat acidity value of 20."
92. Zeleny, Lawrence. Milling deteriorated wheat. Am. Miller Vol. 69,
No. 11, pp. 34-37. November 194-1.
Deterioration is measured by amount of free fatty acids.
"The Agricultural Marketing Administration is developing another
type of test that may prove to be of value as an index of wheat and
flour deteriorations. This test is designed to measure gluten pro-
tein in either wheat or flour by a method that utilizes the photo-
electric cell or so-called 'electric eye. 1 The method is considerably
simpler than the conventional Kjeldahl test and has the distinct
advantage of being a measure of gluten protein rather than total
protein content. Deterioration of wheat or flour in storage is fre-
quently accompanied by a degradation of the gluten. This test is
still in the developmental stage."
Fatty acid (see .
24,26, 4 i
Change during i
t on s
Germination (see Viability)
Flour (see Flour)
Heat damage (see Damage)
Hermetically sealed (see
' j >
Linoleic (see Acid)
Linolenic (see Acid)
Linolic (see Acid)
Milling quality (see
49,50, 52, 6l!
Cause of dcteriorj
Mus tines s